Transcription factor regulation of prodynorphin gene expression following rat hindpaw inflammation.
Both c-Fos and prodynorphin mRNA and peptide increase unilaterally in nociceptive-specific neurons in the lumbar rat spinal cord during chronic hindpaw inflammation. To study the mechanisms underlying prodynorphin gene expression, we examined transcription factors and their interactions at the CRE/AP-1-like site, DYNCRE3, found in the prodynorphin gene promoter. CREB repressed while c-Fos and c-Jun activated transcription through the DYNCRE3 site in transient co-transfections in PC12 cells. Following inflammation of the rat hindpaw, immunostaining demonstrated a bilateral increase in phosphorylated CREB (P-CREB)-positive neurons in the spinal cord. Gel supershift studies showed that spinal cord extracts contained CREB, P-CREB, and phosphorylated c-Jun (P-c-Jun) proteins that bound to the DYNCRE3 site. We propose a model in which inflammation-induced phosphorylation of CREB relieves CREB repression at the DYNCRE3 site, P-CREB binds to the c-Fos promoter, and Fos/Fra, P-CREB, and P-c-Jun interact at the DYNCRE3 site to activate prodynorphin gene transcription.
Messersmith
D J
DJ
Pain and Neurosensory Mechanisms Branch, National Institute of Dental Research, NIH, Bethesda, MD 20892, USA.
Kim
D J
DJ
Iadarola
M J
MJ
D000818:Animals; D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000096:biosynthesis / Q000378:metabolism; D004745:Enkephalins / Q000096:biosynthesis*; D005786:Gene Expression Regulation; D006614:Hindlimb; D007249:Inflammation / Q000378:metabolism*; D008297:Male; D008959:Models, Neurological; D009474:Neurons / Q000378:metabolism* / Q000502:physiology; D016716:PC12 Cells; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011498:Protein Precursors / Q000096:biosynthesis*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000096:biosynthesis; D013116:Spinal Cord / Q000378:metabolism* / Q000503:physiopathology; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
D017362:Cyclic AMP Response Element-Binding Protein; D004745:Enkephalins; D011498:Protein Precursors; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D011994:Recombinant Proteins; D018808:Transcription Factor AP-1; D014157:Transcription Factors; C033660:preproenkephalin